This invention relates to pulsed gas lasers and particularly to the type employing sheet-form transmission lines as the source of excitation, in a Blumlein pulse circuit. In such lasers a pair of parallel, coextending sheet-form conductors separated by a thickness of dielectric defines a capacitor which stores electrical energy. A discharge gap in one of the conductors is filled with active lasing gas. By rapid initiation of discharge of the capacitor, as by a spark gap device, the voltage wave propagating through the sheet-form conductor produces an electrical discharge at the gap resulting in lasing action in the gas. For further background the disclosure of U.S. Pat. No. 3,757,248 is incorporated by reference.